The present invention relates to a temperature control device for a head of a thermal printer which accurately controls the temperature of the head by compensating for a difference between an actual head temperature and a sensed head temperature.
The problem heretofore encountered with a thermal printer is that when the temperature of a head thereof undergoes a sharp change, it cannot be controlled with accuracy resulting in a decrease in the density of images to be printed out, a decrease in the service life of the head, and other undesirable occurrences. In light of this, it has been customary to protect the head by presetting a critical temperature level, or overheat level, of the head relatively low. This, however, causes the operation of the head and, therefore, that of the whole printer to be interrupted even when the head temperature has not been elevated to an actual overheat level. Conversely, should the overheat temperature of the head be designed relatively high, an elevation of the head temperature beyond the actual overheat level would fail to be detected to shorten the life of the head or even immediately break down the head.